Evaluation of an Asphalt USAF Radar Landing Pad

Location: Lajas, Puerto Rico

A radar landing pad in Lajas, PR serves vehicles that are used to deploy a blimp carrying surveillance equipment. The landing pad is a large circular, paved area with a diameter of approximately 200 m. Most of the landing pad is paved with asphalt, with the exception of a centered circular area, with a diameter of about 55 m, which is paved with concrete. As a result of age, the asphalt concrete portion of the landing pad was rehabilitated in early 2010. The rehabilitation involved milling and resurfacing with asphalt, along with some full-depth asphalt repair. A few months after the rehabilitation project was completed, the surface of the asphalt exhibited distress in the form of surface shear, or tearing. Carrasquillo Associates (CA) was hired to characterize the pavement distress and to review the rehabilitation design and construction records. CA performed independent pavement design calculations using the design and current heavy forklift traffic conditions. CA also reviewed the contractor’s asphalt mixture design and quality control records, which included mixture property characteristics and compaction data. The distress was indicative of heavy forklift traffic exceeding the design loading for the pavement. A rehabilitation option using a rigid pavement surface, of either portland cement concrete or resin-modified pavement was also evaluated.